如何在 Java 中获取正在运行的线程的优先级

问题描述

如何获取正在运行的线程的优先级?

解决方案

以下示例使用 setPriority() 方法打印正在运行的线程的优先级。

public class SimplePriorities extends Thread {
   private int countDown = 5;
   private volatile double d = 0; 
   public SimplePriorities(int priority) {
      setPriority(priority);
      start();
   }
   public String toString() {
      return super.toString() + ": " + countDown;
   }
   public void run() {
      while(true) {
         for(int i = 1; i < 100000; i++) d = d + (Math.PI + Math.E) / (double)i;
         System.out.println(this);
         if(--countDown == 0) return;
      }
   }
   public static void main(String[] args) {
      new SimplePriorities(Thread.MAX_PRIORITY);
      for(int i = 0; i < 5; i++)
      new SimplePriorities(Thread.MIN_PRIORITY);
   }
} 

结果

上述代码示例将产生以下结果。

Thread[Thread-0,10,main]: 5
Thread[Thread-0,10,main]: 4
Thread[Thread-0,10,main]: 3
Thread[Thread-0,10,main]: 2
Thread[Thread-0,10,main]: 1
Thread[Thread-1,1,main]: 5
Thread[Thread-1,1,main]: 4
Thread[Thread-1,1,main]: 3
Thread[Thread-1,1,main]: 2
Thread[Thread-1,1,main]: 1
Thread[Thread-2,1,main]: 5
Thread[Thread-2,1,main]: 4
Thread[Thread-2,1,main]: 3
Thread[Thread-2,1,main]: 2
Thread[Thread-2,1,main]: 1
.
.
.